A Niagara system will only use one spawn rate curve when it has more than one emitter with different spawn rate curves

A Niagara system will only use one spawn rate curve when it has more than one emitter with different spawn rate curves

Systems that have more than one emitter that both have unique spawn rate curves will only used the most recently added emitter's spawn rate curve for all emitters.

Steps to Reproduce

Create a Niagara emitter based on the fountain template

Set its spawn rate to Float from Curve

Edit the curve so that it has two peaks, one at the end and one at the beginning, with no particles spawning in the middle

Create another emitter based on the fountain

Change its color curve to visually distinguish it from the first one

Set its spawn rate to Float from Curve

Edit the curve so that it has one peak in the middle, with no particles spawning at the start or end.

Create a system with the first emitter, and observe that the particles spawn in the same pattern as the emitter

Add the second emitter to the system.

RESULT

When the second emitter is added the spawn curve for the second emitter is used for both emitters. The first emitter will stop spawning particles at the start and end of the loop, and will now spawn them in the middle.

Have Comments or More Details?

There's no existing public thread on this issue, so head over toAnswerHub just mention UE-77625 in the post.